Method of knitting a tube with a closed end

ABSTRACT

A METHOD OF FORMING A CLOSED OR PARTIALLY CLOSED FABRIC TUBE ON A KNITTING MACHINE WHEREIN AN END POUCH IS FORMED BY KNITTING DOUBLE FABRIC IN THE MANNER OF A TURNED WELT FROM A YARN OR YARNS HAVING A HIGH DEGREE OF TWIST LIVELINESS, THE EFFECT OF THE TWIST LIVELINESS BEING TO CAUSE THE WALES IN ONE PLY OF THE WELT TO DEVIATE SLANTWISE IN ONE DIRECTION AND THE WALES IN THE OTHER PLY OF THE WELT TO DEVIATE SLANTWISE IN THE OPPOSITE DIRECTION, THE FABRIC BEING THEREBY CAUSED TO BECOME TWISTED SO THAT AT THE FOLD OF THE WELT-LIKE PORTION IT IS CONSTRICTED TO A SUBSTANTIAL OR COMPLETE CLOSURE, AND ALSO A TUBULAR KNITTED FABRIC HAVING A SUBSTANTIALLY OR COMPLETELY CLOSED POUCH AT ONE END PRODUCED BY SUCH METHOD.

Dec. 14, 1971 N ETAL METHOD OF KNITTING A TUBE WITH A CLOSED END Filed Jan. 10, 1969 2 SheetsSheet 1 FIG. 3.

Dec. 14, 1971 H.WIGNALL ETAL 3,626,724

METHOD OF KNITTING A TUBE WITH A CLOSED END Filed Jan. 10, 1969 2 Sheets-Sheet 2 United States Patent US. Cl. 66-14 5 Claims ABSTRACT OF THE DISCLOSURE A method of forming a closed or partially closed fabric tube on a knitting machine wherein an end pouch is formed by knitting double fabric in the manner of a turned welt from a yarn or yarns having a high degree of twist liveliness, the effect of the twist liveliness being to cause the wales in one ply of the welt to deviate slantwise in one direction and the wales in the other ply of the welt to deviate slantwise in the opposite direction, the fabric being thereby caused to become twisted so that at the fold of the welt-like portion it is constricted to a substantial or complete closure; and also a tubular knitted fabric having a substantially or completely closed pouch at one end produced by such method.

This invention is for improvements in tubular knitted fabric and is concerned with the closure or partial closure of a knitted tube during the course of the knitting procedure, thereby avoiding the need for a subsequent closure operation. The invention has for one of its objects to provide a convenient and effective way of closing a fabric tube which is capable of being practised without substantial alteration to existing knitting machines.

In accordance with the invention there is provided a method of forming a closed or partially closed fabric tube on a knitting machine in which an end pouch which is wholly or partially closed is formed by knitting double fabric in the manner of a turned welt such double fabric being knitted from yarn or yarns having a high degree of twist liveliness causing the wales of one ply of the fabric to deviate slantwise in one direction and the wales of the other ply of the fabric to deviate slantwise in the opposite direction, the fabric being thereby caused to become twisted so that at the fold of the welt-like portion it is constricted to a substantial or complete closure. The welt-like portion may be formed at the commencement or termination of the tubular fabric. If formed at the termination, i.e. after the main body of the tube has been knitted it will be followed by courses of anti-ravel fabric. The invention makes use of the known tendency to slantwise deviation of wales in fabric knitted from highly twist lively yarn and by turning a piece of fabric having such deviated wales in the manner of a double welt the deviation is utilised to cause twisting of the fabric to constrict it to a substantial or complete closure giving an appearance somewhat like an iris diaphragm. Depending on the length of the fabric incorporated in the double thickness part and the degree of twist liveliness in the yarn, the fabric can be caused to become closed to a greater or less extent.

A pouch formed in the manner above indicated can be caused to be more completely closed by manipulation of the double fabric, for example manually, in such manner as to concentrate the greatest twisting of the fabric at the region of the fold between the two plies of the double fabric. It can thus be arranged that a substantially completely closed pouch form can be produced and by knitting it from yarn which is capable of being set by the 3,626,724 Patented Dec. 14, 1971 ice aid of heat treatment, such as yarn of nylon or other manmade fibre having similar capabilities of being heat set, a closed pouch can be produced which is set in its closed form and thus remains permanently closed for all practical purposes. On the other hand before the fabric is set, the twist of the fabric can if desired be spread out along the length of the fabric which is doubled in which case an open ended pouch can be produced. This facility makes it readily possible to knit a tubular blank on a circular knitting machine with the main part of the blank knitted first and the double fabric portion knitted afterwards as a continuous extension from the main part and formed on the machine outside the said main part, so that afterwards the part of the tubular fabric around which the double thickness portion is formed can be drawn through the double thickness portion leaving the termination of the latter on the inside of the fabric. The double fabric is afterwards manipulated to concentrate the twist at the fold and thereby close it fully and the fabric is set in this condition. Thereby the final anti-ravel courses can be caused to be concealed on the inside of the pouch. This manner of procedure is advantageous in the manufacture of tubular knitted stockings, socks and other knitted garments having foot portions, to which the invention may be applied. The invention enables a closed toe pouch for such footwear to be formed on the machine on which the garments are knitted.

As above indicated the degree of closure of the pouch is related to the degree of twist or liveliness in the yarn and to the length of fabric knitted to form a double thickness part, the closure being more complete with a longer length of fabric than with a short length. In order to enable a shorter length of fabric to be formed into a pouch it is advantageous in practising the invention to knit the end pouch in three sections, two of which are knitted from a yarn or yarns having a high degree of twist or twist liveliness and the remaining section, which is interposed between the other two, being knitted from a different yarn. The intermediate section forms the fabric at the region of the fold of the double fabric.

It has been found that considerable benefit is obtained by employing at what ultimately becomes the folded position of the double fabric a yarn that differs from that used in the rest of the double fabric. Depending on the type of article, e.g. hosiery or other garment, being knitted, the yarns will be varied in the double layer portion to suit the fabric knitted in the other parts of the article and the type of yarn used at the fold position may also need to be varied to suit the double layer fabric.

The yarn used in the intermediate section at the region of the fold is desirably a non-torque yarn as this will assist (as explained later) in securing a substantially complete closure of the fabric in a comparative short length of pouch fabric.

A yarn which may in some circumstances be used advantageously for the fold zone is an elastomeric yarn, for example one as sold under the trade name Vyrene. By using a yarn of this type, and suitably adjusting the stitch length, considerable contraction of the tube can be obtained. When such a yarn is used in the fold zone of double fabric knit from twist lively or torque yarns as above described, the closure becomes particularly effective.

The invention includes a tubular knitted fabric having a pouch atone end which is completely or substantially closed by being formed of double fabric (in the manner of a turned welt) knitted from yarn having a high twist liveliness which has caused the double fabric at the fold thereof to become twisted to partial or complete closure. Such a fabric tube may be heat set to cause it to adopt a permanently closed or substantially closed form at the pouch end. The invention also includes a knitted blank for a garment having a foot portion in which the toe pouch is formed by double fabric as aforementioned.

The knitted blank as aforesaid may include an intermediate zone at the fold parts of the double fabric such intermediate zone being knitted from a different yarn (e.g. a non-torque yarn) from that used in the remainder of the double fabric. Such a knitted fabric article may be produced on a knitting machine by a method in which an end pouch which is wholly or partially closed is formed by knitting double fabric in the manner of a turned welt, such fabric being knitted from a yarn or yarns having a high degree of twist liveliness in conjunction with a further yarn of different character, the latter yarn being knitted in that portion of the fabric which ultimately constitutes the fold zone of the double layer portion.

Certain convenient procedures in accordance with the invention will now be described by way of example with reference to the accompanying drawings in which:

FIG. 1 is a somewhat diagrammatic perspective view of the toe end portion of a completed stocking blank showing a substantially closed toe pouch;

FIG. 2 is a diagrammatic perspective view of the welt like fabric shown for convenience opened out before it is turned to double it;

FIG. 3 is a view corresponding to FIG. 1 showing the fabric after turning but in an open ended condition;

FIG. 4 shows the fabric of FIG. 3 in the closed ended condition, and

FIGS. 5, 6 and 7 are views corresponding to FIGS. 2, 3 and 4 but illustrating a modified procedure.

Examples of ways of practising the invention illustrated in the accompanying drawings refer to the production of a tubular knitted blank, for example for a stocking, sock or other footwear article, knitted either toe end last or toe end first with the toe pouch formed and closed on the knitting machine being constructed in the manner of a turned welt knitted from a yarn having a high degree of twist liveliness. A suitable yarn to employ for this purpose is multi-filament false twist yarn of nylon or other man-made fibre having similar heat setting properties, such yarn being a texturised yarn with residual torque. When relaxed the yarn has a tendency to either S or Z twist.

In FIG. 1 there is illustrated the toe end part of the foot portion of a footwear article knitted on a circular knitting machine as a tubular blank. The main part of the foot is indicated at 10, and a toe pouch at 11 knitted in the manner of a turned welt and joined to the foot part at a join line 12. The wale lines of the foot portion 10 are indicated at 13 and extend parallel or substantially so to the longitudinal centre line of the foot. The toe pouch 11 is as above indicated knitted from torque yarn having a high degree of twist liveliness which causes the wale lines in the toe pouch indicated at 14 to extend slantwise or obliquely in spiral fashion and cause the double thickness welt portion to become constricted to a substantially closed condition at 15 on the fold line of the folded back or double welt like portions. Since the twist liveliness of the yarn causes the wales of the fabric to twist spirally in one direction in one ply of the welt and the turning of the welt bringg them back spirally in the opposite direction in the other ply of the welt, the central part of the welt fabric located at the fold of the welt is subjected to twisting so as to bring it to a closure. In constricting the fabric in this manner oppositely slanting pleats of spiral form indicated at 16 are formed in the fabric.

In the construction of FIG. 1 the footwear article may be knitted with the toe punch 11 as the first formed or last formed part. If it is the last formed part the procedure will be as illustrated diagrammatically in FIGS. 2, 3 and 4. FIG. 2 shows for convenience in understanding a longitudinally spread length of tubular fabric constituting the toe pouch 11 and one of the slanted wale or obliquely extending lines is seen at 14. It is formed around the tubular blank or foot portion 10 and attached to the latter along the join line 12. When the welt is turned the bottom part of the fabric 11 is drawn up over the upper part thereof and its end indicated at 17 in FIG. 2 is joined to the other end along the join line 12 in accordance with known procedure. The joining is effected so that each wale has its ends brought together or, in other words, the wales on the folded back portion are prevented from laterally or transversely displacing with respect to their other ends which are contained in the unfolded back or remaining portion. This condition is illustrated in FIG. 3 with the doubled welt like fabric 11 held in an open condition, a small number of antiravel courses indicated at 18 being knitted beyond the join 12 so that the footwear article can then be pressed off the knitting machine. The condition of FIG. 3 is one which will only exist in practice if the fabric 11 is held outwardly by being engaged by an inner member passing through the tubular fabric. When it is not so held the twist liveliness of the yarn causing the slant of the wales 14 will cause the fold line of the welt to become constricted to a substantially closed condition as shown in FIG. 4. In this figure the constriction of the portion 11 embraces part of the foot fabric 10 but it will give sufficiently to enable the foot fabric to be drawn through the constriction and the toe pouch 11 to be drawn through the constriction and the toe pouch 11 to be turned inside-out through the restriction bringing the anti-ravel band 18 to the inside of the finished article.

The fabric forming the foot and welt-like portion is knitted on a circular knitting machine with the first course of the toe portion retained on welt hooks or similar instruments and when a sufificient length of fabric has been completed the loops held by the welt instruments are returned to the needles in the known manner of turning a stocking welt. This results in the formation of a double thickness fabric in which the wales are deflected to a very marked extent slant-wise giving rise to a twist in the doubled fabric which causes the fabric in the neighborhood of the fold of the welt-like structure to become accumulated and constricted towards the centre of the tubular formation.

After the footwear blank has been completed it is shaped and set on a board or form and in shaping the toe end it may be advantageous to work the twist of the fabric toward the fold of the welt so as to concentrate the twist in the fabric at the closed end 15 of the pouch 11 thereby assisting substantially complete closure. The toe end is set with the remainder of the foot-wear article by the normal setting treatment causing it to retain more or less permanently the closed pouch formation. The procedure just described involves no modification in structure in a circular knitting machine as commonly used for knitting stockings to enable it to be produced. All that is required is a suitable adjustment of the machine to provide for the sequence of yarn changes required for introduction of the twist lively yarn, and the required action of the welt books or other holding instruments to form the welt like toe portion. In some circumstances however it may be found desirable in order to provide a more complete closure of the pouch to impart a partial twist to the double fabric by causing a relative turning movement between the instruments which hold the initial loops of the doubled portion and the needles through, for example, up to one quarter or one half of a rotation before transferring the initial loops back to the needles at the completion of the double welt-like toe portion 11.

In an example of a modified procedure illustrated in FIGS. 5 to 7 of the drawings a welt like portion of knitted fabric to form a toe pouch may have its first course retained on welt hooks or instruments capable of having a similar action. Such instruments may be constituted by the rib needles of a two bed opposed cylinder or cylinder and dial circular knitting machine of the type as used for the knitting of ribbed and fancy hosiery for both mens and womens Wear.

Assuming the toe pouch is knitted first, make up courses of fabric are first formed on the needles in known manner and with a one and one set out of the needles alternate loops are retained on the rib needles which are then directed to a non-knit loop holding position and a yarn change is made to introduce a torque or twist lively yarn to the plain needles. At this stage it is preferable to knit with a minimum of fabric drawoff tension, the knitting taking place on the plain needles only. A number of courses e.g. about forty, are knitted from the torque or twist lively yarn and then a yarn change is made to substitute a different yarn (conveniently a non-torque yarn which if desired may be an elastomeric yarn) for a few courses, e.g. about ten. The yarns are then changed to bring back the torque yarn for knitting the second part of the double layer fabric which may consist of forty courses to match the initial portion. Having completed this last section the rib needles are brought out of loop holding inactivity and a transfer is made to join the held loops of the initial course of the double fabric portion to the last knit course so that the welt like loop of fabric is closed. If a double cylinder knitting machine is being used, this transfer is done simply by returning the rib needles back to the bottom cylinder and continuing the knitting on all needles. At the transfer stage the fabric draw-off tension is restored to normal.

As described above the automatic closure of the fabric tube is brought about by the action of the torque or twist lively yarn, which causes the wales to deviate slantwise relatively to the axis of the tube, together with the action of doubling the fabric of the tube.

FIG. shows three sections of tubular fabric indicated at 20, 21, and 22 which may be knitted either before (as shown) or after the continuing portion of fabric 23.

The portions 20 and 22 which are to form the main parts.

of the welt double fabric after turning has occurred are knitted from torque or twist-lively yarn, while the portion 21 is knitted from non-torque yarn which may, if desired, be elastomeric. The characteristic of the yarn in the portions 20 and 22 tends to cause the wale lines to adopt a slanted form as indicated at 24 and 25. The lines 24 and 25 represent the positions of a wale knitted on the same needle, this wale being held at one end by a hook or other similarly acting instrument and at the other end by the needle on which the wale is knitted. Due to the slanting tendency of the wale lines 24 and 25 there'is a tendency to stretch and cause opposite slant to the corresponding wale line 26 in the portion 21 of the fabric. The turning of the welt like portion causes the first course line indicated at 27 in FIG. 5 to be joined to the last course line indicated at 28 in that figure (on the inside thereof when the toe is knitted first) and this causes the wales of the outer layer to lie over in the opposite direction to the wales of the inner layer. Because each wale has its ends joined together, as shown diagrammatically at 31 in FIG. 6, the outer tube twists towards the fold 32 in one direction indicated by the wale line 33, (correspond ing to 24 in FIG. 5) while the inner tube twists towards the fold in the opposite direction indicated by the dotted wale line 330 (corresponding to 25 in FIG. 5). The result of this is to cause contraction of the fabric at the fold line, giving an appearance somewhat like an iris diaphragm (see FIG. 7). By knitting a few courses of non-torque yarn at the fold zone 21 as already described, the twisting action is more readily concentrated at the region of the fold 32 between the two plies 20 and 22 of the double fabric. When the non-torque yarn is an elastomeric yarn, an additional constriction of the fabric tube may be obtained.

FIG. 6 shows the fabric in an outwardly stretched condition which will in practice only exist if it is held outwardly by being engaged by an inner member passing through the tubular fabric. In actual practice due to the stresses set up by the tendency to slantwise deflection of the wales the double fabric portion will be drawn to a closed or substantially closed formation illustrated in FIG. 7 in which the central opening through the fabric is drawn completely closed at the fold 32, the closure point being indicated at 29. The slantwise deflection of the wale lines may in fact be at least sufiicient to cause the fabric 21 in the fold region 32 to have its knitted wales drawn more or less to U-loop form partly surrounding the closure point 29.

The above described procedures provide improved methods for closing a fabric tube on a knitting machine, and when applied to the knitting of hosiery may be used to form a closed toe pouch either at the commencement of knitting the hosiery article or at the final stage. In the latter case, anti-ravel courses as at 18 (FIGS. 3 and 4) will be knitted after the toe pouch fabric has been turned. The anti-ravel courses may be formed in any convenient manner permitting them to have elasticity. Again, when knitting the closure at the final stage, because the sock or stocking is suspended temporarily from the rib needles (or welt hooks as the case may be) while knitting of the double fabric portion takes place, the anti-ravel courses are so positioned that they will not appear on the surface of the finished article. Although the double fabric portion is knitted around the outside of the suspended sock or stocking, the toe end portion, after release from the needles, must be drawn through the resilient closure and this will bring the anti-ravel courses to the inside and allow the inherent twist in the double fabric fully to close the tube.

The herein described procedures may be practised either when knitting a succession of separate articles or when knitting articles connected end to end in string formation. In the latter case, having knitted the closure and anti-ravel courses, a welt of the next succeeding article may be made in normal manner, and separation of the articles may be obtained either by the withdrawal of a draw-thread or by cutting through waste fabric adjacent to the anti-ravel courses.

It will be appreciated that the yarn employed for kniting the double welt-like portion may be varied to suit particular requirements. In general it will be found particularly advantageous to employ a bulked yarn of manmade fibre with the bulking produced by a twisting or false twisting procedure causing the yarn to possess a high twist liveliness giving a tendency for S- or Z-twist.

It will be evident that the double welt-like portion of fabric forming a pouch as aforementioned may be knitted on a circular knitting machine having a single feeding and knitting station or a plurality of such stations spaced apart around the needle circle. Also if desired such a pouch may be knitted from a plurality of yarns fed to the needles simultaneously at one feeding station. The direction in which the twist lively yarn tends to twist may be either an S-twist or a Z-twist to suit particular circumstances, e.g. the direction in which rotary knitting is performed.

It will be apparent that the invention may be applied to the manufacture of other knitted goods besides hosiery such as hats, berets and other similarly knitted articles. It will also be apparent that, although the invention has been described by way of example in relation to a double layer of fabric made on the inwardly turned welt principle, it could equally well be practised by knitting the double fabric on the outwardly turned principle, without requiring a second instrument bed.

In practising the invention it may be found advantageous to employ as a torque or twist-lively yarn for knitting the portions of fabric forming the layers of the double layer fabric, a yarn which has its torque properties rendered dormant so as to be inactive during the knitting procedure and capable of being released by the finishing process. Advantageously this type of yarn may be employed for forming a closure portion of a fabric tube whether or not an intervening part such as 11 is provided knitted of non-torque yarn. Accordingly the invention includes a method of forming a closed or partially closed fabric tube on a knitting machine in which an end pouch which is wholly or partially closed is formed by knitting double fabric in the manner of a turned welt such double fabric being knitted from a yarn or yarns having torque or twist-lively characteristics which are maintained dormant during the knitting procedure and subsequently treating the tube to cause the torque or twist lively characteristics of the yarn to become effective.

An alternative way, in practising the invention, of producing the double-layer fabric is to knit one yarn supplied by one feeder on needles of an upper needle bed while knitting another yarn supplied by another feeder on needles of a lower needle bed, thus producing two layers of tubular fabric, one within the other, joined by at least a course or two of single fabric at the start the yarns having each an appropriate direction of torque or twist liveliness. When an intermediate section of fabric, such as 11, is required, a non-torque yarn is supplied at one or both of the feeder positions to provide the intermediate courses which join the two layers together. The transition to single layer knitting can be made to take place when required by transfering fabric loops from needles of the upper bed down to the lower bed (e.g. by transfering needles from the top cylinder to the bottom cylinder of a double cylinder machine). Knitting then takes place on the lower bed only and on all needles so as to join the layers of fabric together at the finish of the double fabric.

What we claim is:

1. In a method of knitting a fabric tube open at one end on a circular knitting machine, the method of substantially closing the other end of said tube which comprises the steps of knitting at said other end of the tube, a tubular fabric to be doubled having three axially consecutive sections, the first and last of said sections being knitted of consecutive courses of at least one yarn having a high degree of twist liveliness and the intermediate section in which the fold of the double fabric is to be formed being knitted from a yarn of different characteristics, doubling said tubular fabric by folding the same at said intermediate section and joining the ends of said first and last sections at a junction line with at least approximately the same wales of said first and last sections joined to one another without rotation of said ends relative to one another to form a two-ply fabric in which the wales of said first section twist spirally in one direction from said junction line due to the twist liveliness of the yarn of which it is knit and the wales of said last section twist spirally in the opposite direction from said junction line due to the twist liveliness of the yarn of which it is knit to effect a concentrated twisting of the fabric of said intermediate section in an opposite direction by the reverse spiral twisting of the wales in said first and last sections to constrict said tubular fabric of said intermediate section to a substantially closed condition, the yarn of which said intermediate section is knit being of a character to facilitate said reverse twisting.

2. A method according to claim 1, wherein said intermediate section is knit of a non-twist-lively yarn.

3. A method according to claim 1, wherein at least one said yarn is heat settable, further including the step of heat setting said yarn after constriction of said tubular fabric of said intermediate section to a substantially closed condition.

4. A method according to claim 1, further including the step of knitting an anti-ravel band around the junction of the ends of said first and last sections.

5. A method according to claim 1 wherein the yarn used to knit said intermediate section is an elastomeric yarn and the stitch length in said intermediate section is adjusted to promote contraction of the tubular fabric thereat.

References Cited UNITED STATES PATENTS 2,274,812 3/1942 Smetana 66173 2,397,460 4/1946 Bell. 2,702,998 3/1955 Purcell 66178 A 2,741,825 4/1956 Runton et al. 2,747,390 5/1956 Reymes-Cole 66173 2,796,655 6/1957 Stuewer 66202 X 2,994,214 8/1961 Wood, Jr. et a1. 66178 A 3,077,757 2/1963 Bobo, Jr. et a1 66178 A 3,109,278 11/1963 Gibson, Jr. 3,210,964 10/1965 Russell 66l78 A 3,327,500 6/1967 Currier 66187 3,375,684 4/1968 Page 66178 A 3,395,554 8/1968 Wallner, Jr. 66172 3,415,081 12/1968 Anderson. 3,453,843 7/1969 Knohl et a1.

FOREIGN PATENTS 966,295 8/1964 Great Britain.

1,430,729 1/1966 France.

WM. CARTER REYNOLDS, Primary Examiner US. Cl. X.R. 

